I've still got a model 55* Safariland duty holster & belt I bought in 1969 or early 1970. The thumb break safety strap passed between cocked hammer & slide rear as an additional safety barrier. It did have the unfortunate tendency over time to work the thumb safety off when you wiggled around on the seat. It became habit to slide a thumb in the verify safety position while exiting the car.

*Muzzle forward raked 1911 holster.